The surfaces of many functional objects, such as those made of plastic, must have a certain texture for visual or other reasons, so as to provide a uniform degree of roughness, a structure that corresponds to different types of leather, or even a fine porous nature, for example. To obtain these various surface textures, the respective molds, rollers or other shaping elements must undergo an expensive process that involves either cutting, etching, sand-blasting, or the like.
A generic process for structuring a nip roller for cameras is known from U.S. Pat. No. 4,758,705, wherein texturing is performed while the roller is clamped in a turning gear using a pulsed laser beam that traverses the surface of the rollers. The laser beam and the roller are controlled by a control unit such that a predetermined pattern is engraved on the roller. However, the pattern so produced has a uniform texture, and such a textured surface cannot be used as an imitation of a natural material, for example.
German Patent DE 41 02 984 A1 describes a process for producing a surface texture on a roller, wherein the diameter and the depth of recesses on the roller is controlled by a control unit with an electron beam. Also, a random generator is used to determine the texture of a recess in a spatial dimension. According to this publication, textures like steel grit can be simulated, but a lot of computer time is needed to generate such textures. Moreover, the textures so produced are not suitable for imitating random uneven structures, such as leather.
It would be desirable to create a process for texturing the surfaces of workpieces with a laser beam that makes it possible to produce different types of surface structures using different materials in a way that is fast and technically simple.